Nose simulator with multisampling modes for airstream evaluation

ABSTRACT

A nasal simulator includes a three-dimensional (3D) printed nasal cavity within based on diagnostic imagery of a human nasal cavity. The nasal simulator comprising a fan system positioned to mimic air flow through the human nasal cavity. A first probe access bore is formed through the 3D printed nasal cavity to a first location having a first internal contour. An anemometer insert having an outer diameter sized to be slidingly received in and to pneumatically seal the first probe access bore, the anemometer insert having a distal contour that aligns with the first internal contour of the 3D printed nasal cavity, the anemometer insert having a longitudinal bore that is sized to receive a probe of an anemometer to detect characteristics of the air flow through the 3D cavity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(e)to U.S. Provisional Application Ser. No. 62/877,502 entitled “Nosesimulator with multisampling modes for airstream evaluation,” filed 23Jul. 2019, the contents of which are incorporated herein by reference intheir entirety.

This application claims the benefit of priority under 35 U.S.C. § 119(e)to U.S. Provisional Application Ser. No. 63/042,615 entitled “Nosesimulator with multisampling modes for airstream evaluation,” filed 23Jun. 2020, the contents of which are incorporated herein by reference intheir entirety.

ORIGIN OF THE INVENTION

The invention described herein was made by employees of the UnitedStates Government and may be manufactured and used by or for theGovernment of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefore.

BACKGROUND 1. Technical Field

The present disclosure generally relates to anatomically representativetesting apparatuses, and more particularly to nose simulator systems.

2. Description of the Related Art

The air flow and spatial distribution patterns within different regionsof the nasal cavity are variable and complex, and more preciseenvironmental monitoring systems that simulate the actual patternedairflow distribution within the nasal cavity are needed to make morerealistic and informative evaluations of air quality and theconsequential health effects of inhaling different atmosphericcompositions.

BRIEF DESCRIPTION OF THE DRAWINGS

The description of the illustrative embodiments can be read inconjunction with the accompanying figures. It will be appreciated thatfor simplicity and clarity of illustration, elements illustrated in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements are exaggerated relative to otherelements. Embodiments incorporating teachings of the present disclosureare shown and described with respect to the figures presented herein, inwhich:

FIG. 1 a three-dimensional (3D) view of a 3D printed breathing humannose simulator for environmental screening and respiratory research,according to one or more embodiments;

FIG. 2 depicts a flow diagram of a method used to create the 3D printedbreathing human nose simulator of FIG. 1, according to one or moreembodiments;

FIG. 3A is a 3D view of the construction of the nasopharynx base object,according to one or more embodiments;

FIG. 3B is a top front view of the nasopharynx base object of FIG. 3A,according to one or more embodiments;

FIG. 3C is a left view of the nasopharynx base object of FIG. 3A,according to one or more embodiments;

FIG. 4A is a front view of a portion of 3D printed nasal cavitycontained in a first slide, according to one or more embodiments;

FIG. 4B is a front view of a portion of 3D printed nasal cavitycontained in a second slide, according to one or more embodiments;

FIG. 4C is a front view of a portion of a 3D printed pharynx of the 3Dprinted nasal cavity contained in a last slide, according to one or moreembodiments;

FIG. 5A depicts a right side view of the nasopharynx base object,according to one or more embodiments;

FIG. 5B depicts a left side view of the nasopharynx base object,according to one or more embodiments;

FIG. 6A depicts a front view of a first slide having one right probeaccess bore and one left probe access bore, according to one or moreembodiments;

FIG. 6B depicts a front view of second slide having three right probeaccess bores and three left probe access bores, according to one or moreembodiments;

FIG. 6C depicts a front view of a third slide having three right probeaccess bores and two left probe access bores, according to one or moreembodiments;

FIG. 6D depicts a front view of fourth slide having two right probeaccess bores and two left probe access bores, according to one or moreembodiments;

FIG. 6E depicts a front view of fifth slide having three right probeaccess bores and three left probe access bores, according to one or moreembodiments;

FIG. 6F depicts a front view of sixth slide having one right probeaccess bore and one left probe access bore, according to one or moreembodiments;

FIG. 7A depicts a side view of a cylindrical rod of a particular lengthcorresponding to a probe access bore and having a perpendicular distalface that aligns with a perpendicular contour at a location of a 3Dprinted nasal cavity, according to one or more embodiments;

FIG. 7B depicts a side view of a cylindrical rod of a shorter particularlength corresponding to a shorter probe access bore and having anon-perpendicular distal face that aligns with a non-perpendicularcontour at a location of the 3D printed nasal cavity, according to oneor more embodiments;

FIG. 7C depicts an anemometer being inserted through an anemometerinsert that was custom design to fit a commercial miniature sphericalprobe of a flow meter, according to one or more embodiments;

FIG. 7D depicts the anemometer inserted through the anemometer insert ofFIG. 7C, according to one or more embodiments;

FIG. 7E depicts the anemometer inserted through an anemometer insertthat has a non-perpendicular distal face, according to one or moreembodiments;

FIG. 7F depicts a tissue insert having a cylindrical shaft of a lengthselected to position a tissue holder, according to one or moreembodiments;

FIG. 8A is an exploded 3D view of the bi-directional fan that includes astand that includes a motor encasing that mounts to back cover that inturn attaches to a front cover having a mount, according to one or moreembodiments;

FIG. 8B is a side view of the bi-directional fan depicting assembledback and front covers to form a top air port and a bottom air port,according to one or more embodiments;

FIG. 8C is a back view of the bi-directional fan depicting a motor thatincludes motor set-screw and ball bearing to stabilize fan blade spin,according to one or more embodiments;

FIG. 8D is a front view of the bi-directional fan depicting the mountthat is attachable to a side wall of the fan container of FIG. 1,according to one or more embodiments;

FIG. 9A depicts a graphical plot of a normal breathing patterninhalation/exhalation airflow patterns, according to one or moreembodiments;

FIG. 9B depicts a graphical plot a forced breathing patterninhalation/exhalation airflow patterns, according to one or moreembodiments; and

FIG. 10 depicts a screen shot of a Matlab graphical user interface (GUI)used to control flow modes and sequence, according to one or moreembodiments.

DETAILED DESCRIPTION

According to aspects of the present disclosure, FIG. 1 depicts athree-dimensional (3D) view of a nasal simulator 100 that includes athree-dimensional (3D) printed nasal cavity 102 within a chamber 104within based on diagnostic imagery of a human nasal cavity. In one ormore embodiments, the chamber 104 is sectioned into slides 106 a-106 hthat are compressed together by compression screws 108 thatpneumatically sealed the 3D printed nasal cavity 102 that is partiallyincluded in each slide 106 a-106 h, forming an “airlock”. Air canbi-directionally move through nostril holes 107 of first slide 106 a.The chamber 104 is supported on a sliding track system 108 that enableseasy slide securement and manipulation and pharynx-to-fan connection ofslide 106 g through sliding tracking system 108 to a fan system 110 thatmimics bi-directional breathing patterns. A fan 111 of fan system 110 iswithin a fan container 112 that underlies sliding track system 108 andpneumatically communicates with (vents) ambient air via a compressibleexhaust hose 114. Thus, the bi-directional air movement through nostrils107 corresponds to bi-directional air flow movement through compressibleexhaust hose 114. As discussed below, probe access bores 116 are formedthrough the 3D printed nasal cavity 102 to locations of the 3D printednasal cavity 102 having a corresponding internal contour. An anemometerinsert having an outer diameter sized to be slidingly received in and topneumatically seal the first probe access bore, the anemometer inserthaving a distal contour that aligns with the first internal contour ofthe 3D printed nasal cavity, the anemometer insert having a longitudinalbore that is sized to receive a probe of an anemometer to detectcharacteristics of the air flow through the 3D cavity 102.

In one or more embodiments, the nasal simulator 100 includes the chamber104 that provides an upper nasopharynx unit that rests atop the fancontainer 112 that is an acrylic bottom compartment that houses the fan111 and electronic hardware. 3D printed transitional structure 118connects the pharynx portion of the 3D printed nasal cavity 102 to a fanopening of the fan 111 that is centrifugal-like and 3D printed. The fan111 is driven by a 12V DC moto that is capable of generatingbi-directional airflow within the nasal cavity 102.

The nasal simulator enables improved environmental screening andrespiratory research. Distribution of airflow within the labyrinth-likegeometry of nasal cavity is variable and complex. Few bioengineeredsystems fully replicate the anatomically and physiological complexity ofthe upper respiratory system that is required for precise environmentalmonitoring of air quality and the related effects on respiratoryphysiology. With the advent of three-dimensional (3D) printing, complexanatomical models can be readily generated from computed tomography (CT)scans of patients. We detail the design of a 3D printable nose simulatorthat is comprised of a custom bioengineered nasal cast chamber, withanatomically accurate features and autonomous breathing capabilities,which will be ultimately coupled with interchangeable airstream probingmodes to sense air velocity, detect inhalant tissue interactions, andmap distribution of inhaled particulates.

INTRODUCTION: Inspired air entering the nares travels through a closedlabyrinth path shaped by tissue protrusions, called turbinates, whichwarm, humidify and cleanse air (Mistry et al. 2009). Building a 3D nasalcavity structure that preserves this native anatomical intricacy ischallenging and time consuming with commonly-known manufacturingtechniques (Hughes et al. 2008). An automated rapid prototypingplatform, called 3D printing, or formerly additive manufacturing, is apowerful tool for producing highly complex models in a layer-by-layerprocess guided by 3D computer aided design data (Hughes et al. 2008).3D-printing nasal casts have been used for the evaluation of nasalairflow and drug distribution, and also to inform the development ofcomputational models that examine those same parameters (Doody et al.2008, Zhao et al. 2014, Li et al. 2017). Additionally, 3D printed, humanscale models of the nasal cavity, incorporating multiple materials tomimic hard and soft tissue regions, serve as advanced visual-aides andtraining medical tools for the education of patients and students (Dinget al. 2019, Sander et al. 2017a, Sander et al. 2017b, Zhuo et al.2019). More accurate and predictive nasal models are needed frompredictive research to assay toxic threats or therapeutic benefit. Nasalcast models more closely resemble the nasal cavity architecture andphysiological breathing function of humans and cells and tissue permitthe evaluation of biological responses resulting from inhalant exposure.All of these machine and biological elements can be fused together togenerate innovative function biohybrid systems for various forms ofrespiratory research. Here we elaborate on our development of alife-size human nasal cavity, with embedded human tissue regions andbreathing simulator, as a realistic biohybrid robotic model to conductmore physiological relevant assessments for air quality monitoring,nasal drug discovery development, and classic otolaryngologicalresearch.

Primitive processes to fabricate nose models for particle distributionstudies involved the use of cadavers to directly cast nasal cavityregions (Mygind and Vesterhauge 1978, Pu et al. 2014, Pozzoli et al.2016) or to obtain dimensions to guide machining of nasal cavity regionsin select materials (Hallworth and Padfield 1986). Glass pieces withsimplified geometries were machined based on dimensions of nasalfeatures from cadavers (Hallworth and Padfield 1986). Transparentsilicone human nose casts could also be created against positive castsfrom cadavers (Mygind and Vesterhauge 1978, Pu et al. 2014, Pozzoli etal. 2016)) and these type of cast can be readily acquired commercially(Koken Co. Ltd., Tokyo, Japan) (Pu et al. 2014, Pozzoli et al. 2016).The preserved cadaver head itself has also been used as a nasal cast, byimplementing a multi-step process that plasticizes the cadaver headsthrough the displacement of liquids and lipids tissue components with asilicone polymer solution (Durand et al. 2011). More automated andcontemporary strategies involve the use of patient MM scans to create 3Dmodels that guide the rapid prototyping of full negative nasal cavityreplicas (Zhou et al. 2013) or multi-component human nasal casts,partitioned either along the coronal axis or as major subregions of thenasal cavity (Xi et al. 2016, Shah et al. 2013, Foo et al. 2007, Chenget al. 2001, Swift 1991). A series of corona MM images slices arereplicated in up to 100 thin (≤2 mm thick) with micromilling in variouspolymer materials (Foo et al. 2007, Cheng et al. 2001, et al. Swift1991). Other sectional casts are separated in to major vestibule,turbinate and olfactory nose regions, sometimes including throatportions, where individual parts are created with 3D printing methods(Xi et al. 2016, Shah et al. 2013).

While all the aforementioned nasal cast models can supply information onparticle deposition within the upper airway, permit the analysis of theinteraction of particles with the olfactory mucosal cells or tissue.Thus, they do not allow for the examination of absorption of inhaledparticles or the histological examination of tissue subjected to variedtypes of conditioned air and inhalants. Several standard andnon-conventional in-vitro techniques exist for performing nasal studieswith consideration of cellular constituents of the nasal cavity.Standard in-vitro models involve culturing nasal epithelial cell linesat an air-liquid interface in a tranwell well system. In this set-up,cells are cultured atop a porous polymer membrane held in a support thatseparates a culture well into apical and basolateral compartments,respectively devoid and full of nutrient medium (Mercier et al. 2018). Ahandful of newly emergent chip-based systems were designed model anassortment of anatomical and functional features, associated with thenasal cavity (Na et al. 2017, Wang et al. 2014, Figueroa et al. 2010),including nasal glandular structures (Na et al. 2017), cilia beatingpatterns (Wang et al. 2014), and olfaction simulation with olfactorysensory neurons (Datta-Chaudhuri et al. 2016, Figueroa et al. 2010). 3Dprinting has also been implemented to modify a pharmaceutical tool thatpredicts the particle deposition from inhaled drug in the respiratorytract. The instrument traditionally comprises a cascade impactorattached to an induction chamber that respectively characterize particledeposition in the lower and upper respiratory tracts. A 3D printedversion of the induction chamber contained chambers to fit transwellinserts holding ALI-conditioned nasal epithelial cells, and thuspermitted the additional prediction of drug permeability and transportacross the mucosal lining (Pozzoli et al. 2016). Nasal cast designscould benefit from the incorporation of regions that contain nasal cellsor tissue.

Here we describe the construction of a 3D printed human nose simulatorchamber, with anatomical accurate features and breathing functionality.The purpose of the nose simulator chamber is to observe and testdifferent regions within a human nasal cavity replica and detect thephysical effects of airborne particles within a human nose. The nosesimulator chamber will consist of a base nasal chamber, segmented intoequal coronal slices, which includes compartments for probing theairstream to measure air flow speed, particle distribution patterns, andparticle-tissue interactions. A single sampling probe withinterchangeable units used for introducing a flow sensor, TEM screens,and tissue layers within the walls of the interior nasal compartment.

Design and Construction of Nasal Simulator—Nose SimulatorFace/nasopharynx Base: A collection of software was used to convert a CTscan-based stereolithography (STL) file to a face/nasopharynx baseobject, as well as create associated internal and external components.

The nasal cavity file was detected as “empty data” or multivariate data.This data acts as an image within the program and requires furtherprocessing to generate a file that could be edited in the constructionof the nose simulator design. To convert “empty data” into recognizabledata for 3D modeling programs, the nasal cavity file was imported intothe Meshmixer program, a software tool developed to manipulate complexmesh features. Meshmixer was used to reduce the number of vertices andtriangles, defining the nasal cavity design, from 100% to 25%, tooptimize the surface for continuous design edits and changes, andexported as an STL file, compatible with Autodesk Inventor.

Using the MeshEnabler add-on application for Inventor, the nasal cavitywas enhanced by converting all the mesh data from the negative nasalcavity region into a Solid Body part. The Solid Body Part format is aformat where all the mesh data is identical within the .ipt file. ThisSolid Body Part is the optimal format for the additional further designimplementation to 3D models rendered from and advancements on CT scanimaging. Using the MeshEnabler the .stl file of the nasal cavity wasconverted to an .ipt file to allow for editing. To create a 3D mold ofthe negative nasal cavity regions of the .ipt file, an extrusion of77.64×101.96×85 mm was created as a separate solid body part to encasethe nasal cavity and eventually form the negative. We utilized thecombine and subtract tool on Using the newly formed extrusion and thenasal cavity as two solid bodies, the combine and subtract tool was usedto turn two solid bodies into one body. By subtracting the cavity fromthe extrusion it created a negative of the cavity inside the extrusion.

Face/Nasopharynx Base Slides and Complementary Sampling Probes:

The face/nasopharynx base was sectioned into slices, using AutodeskInventor. By integrating a series of planes equidistant from each otherat 9.2 mm, the “Split” command was used to parse the extrusion into 9separate slices. These nasal slices were then exported into an assemblyfor further editing.

Probing regions piercing the thickness of the coronal slices, creatingchannels from the left and right ends of the to the internal cavityfeatures, were designed for all slices, except the first slide thatpresents external facial features, and the last slide that transitionsinto the pharynx region. Coronal sections of the nasal cavity CAD modelwere examined to identify probe sites at the superior, middle, andinferior meatus, the main passages or openings within the nasal cavity.These locations were selected to provide seamless integration withprobes and result in minimal interference with the internal nasalstructures and passages. There were a total of 25 total locationsdispersed throughout the nasopharynx base created twelve (12) for onenostril and thirteen (13) on for the opposing nostril. A 6 mm-cylinderwas cut through each cavity slide at a specified nasal site, resultingin a multi-piece cylinder, broken at open cavity regions, and thenegative of the cylinder. The rod piece with ends containing nasalcavity contours at the site of interest (on either left or right cavityhalf) was saved as a separate file, while the negative of the cylinderand the cylindrical pieces in other regions were fused back together.The two resulting objects were saved as individual files for furthermanipulation. The diameter of the contoured rods were shaved down to 5.6mm to ensure proper tolerances for ease of fitting following printing. Ateeth and groove lock was created to fix each probe into itscorresponding slide. This was achieved by adding two staggered teeth tothe rod piece, 10 mm from the contoured tip, and extruding complementalL-shaped groove paths into the slide. An end piece with an alphanumericlabel and finger grip was combined with the probe body probeidentification and handling. The end piece had a slightly largerdiameter (7.6 mm), and a complemental hole was extruded from the sliceto fit the piece, and the end unit facilitates formation of an airtightlock upon sealing.

To ensure an airtight seal upon stacking all slides, a gasket wasincorporated on the front face of each slide, and threaded openings werebored through each slide on each corner to permit tightening screws.There are three variations (A, B-F, G and end slice variations) ofgaskets that are equidistant to their opposing side 2 mm in width. Eachgasket ring is integrated into a recessed border region of the slide.The gasket has a total thickness of 0.75 mm, with 0.50 mm embedded and0.25 mm protruding, and width of 0.5 mm; these dimensions allow anoptimal level of gasket expansion upon compression.

Cylindrical inserts were designed to fit into each probing site. Therewere three insert variations: (1) a resting insert to fill the openingof a region not being tested, (2) an anemometer insert, to fit a flowmeter probe and sample air flow velocity, and (3) a tissue insert, toexamine the effects of various inhaled airstreams on tissue. All insertsincluded and custom contouring of ends to align with the internalanatomical geometry of the nasal cavity. The cylindrical anemometerprobe was custom designed to hold the omni-directional velocity probe(mini I shape, V, Kanomax, 6551-2G) of a research grade handheldhot-wire anemometer (Kanomax, 6501-CE). The multi-part anemometer rodcontained a channel path for the anemometer probe unit and attached cordand inset to ensure an airtight seal. For the tissue insert probes, acentered circle was extruded from the center of the rod tip to create acylindrical recession for housing tissue-like constructs. The plane ofextrusion plane was set as the lowest geometric polygon on the rod tipand existing within the 4.5 mm diameter circle.

Slides and probe rods were printed with a Stratasys Objet500 polyjet 3Dprinter, using multiple materials: rigid transparent acrylic (VeroClear,Stratasys) for bulk regions of the nasal slides and probes and asemitransparent rubber-like material (Agilus30, Stratasy) for slidegaskets.

Sliding base system: A sliding base system was created to hold and allowbidirectional translocation along the base for easy slide manipulationand access to desired cavity regions. A plastic track was designed witha groove that slid over the ridge at the bottom of a single slide, whilebeing closed at one end to lock the slide in place. All the slide-trackunits were inserted into the grooved aluminum rails (8020.net,25-5013-Black-FB), after which the slides could be compressed togetherand locked in place with the screws. A transitional structure wasdesigned to be integrated into the base system to connect the pharynx ofthe last slide to the opening of the custom fan. The tracks andtransition structure were designed using Autodesk Inventor and producedwith a Carbon Digital Light Synthesis 3D printer, using a rigidpolyurethane material (Carbon, RPU70).

A centrifugal-like fan was created to generate bi-directional airflowwithin the nasal cavity. An .stl file of the fan assembly was designedwith 3D CAD software (Autodesk Inventor) and printed with rigidpolyurethane (RPU, Carbon 3D) material on a digital light synthesis(DLS) 3D printer. The body of the fan is comprised of a cylindricalouter casing with two channels that function as relative inlets andoutlets for airflow. These channels are separated by 90° and residewithin the same plane. The cross-sectional area of both channels is 10mm×18 mm, which is comparable to that of the model's nasopharynx. A5-blade fan (blade length=34 mm) rests on a central axis within thehousing. The fan rotation is driven by a 12V DC motor, positioned nextto the fan axis outside the enclosed casing. A custom-built acrylic boxwas designed to house the fan and electronic hardware.

Fan Integration for Airflow Generation: An Arduino Uno microcontrollerwas used to regulate the amount of voltage and direction of electricalcurrent flow supplied to the motor, which are respectively proportionalto the airflow rate and direction. Voltage applied to the motor can beset between 0-12V, and is proportionally scaled to the Arduino's pulsewidth modulation (PWM) output of 0-5V. This effect was achieved throughuse of a voltage regulator circuit, where the Vin source of 12V wasadjusted to the desired voltage. To simulate both inhalation andexhalation, the current flowing through the motor was reversed through asingle-pull double-relay circuit.

An on-computer GUI, created in Matlab's App Designer Software, is usedto operate the fan unit in the nose simulator. The user is able toselect the desired inhalation and exhalation waveforms and edit theirvarious parameters (i.e. amplitude, breath duration, resting period,etc.). Additional features to compensate for consistency in total lungcapacity (TLC) and back electromagnetic flux (BEMF) of the motor areincorporated into the GUI generated waveforms as well.

Breathing Simulation: A graphical user interface (GUI) for interactingwith fan flow rate and direction was programmed with Matlab's AppDesigner. This GUI application was downloaded and installed on acomputer, independent of a Matlab license requirement. The applicationshares information directly to the simulator device via a USB serialconnection.

RESULTS AND DISCUSSION: In summary, FIG. 2 depicts a flow diagram of amethod 200 used to create the 3D printed breathing human nose simulator100 (FIG. 1). Method 200 includes Data Acquisition: converting CT scansto STL files using Mill Convert software (block 202). Method 200includes Model Decimation: reducing polygons, fuse STL models, & extractartifacts using Meshmixer software (block 204). Method 200 includes Basemodel formation: converting to solid body part using MeshEnablersoftware (block 206). Method 200 includes Surface optimization: removingdefects using molding tool such as Autodesk Inventor software (block208). Method 200 includes Slicing and extrusion: adding probing sitesand gasket routing using Autodesk Inventor software (block 210). Method200 includes Three-dimensional (3D) printing: printing multi-materialobjects using for example Stratasys Polyjet & Carbon 3D printers (block212). Then method 200 ends.

Using a collection of CAD software, 3D printers, machining tools,assorted materials and Arduino electronic platforms, we successfullydesigned a nose simulator system featuring: anatomically-precise humannasal cavity regions, a custom-built fan system to mimic human cyclicand noncyclic breathing patterns, and compartments to probe airstreamfor flow velocity, tissue-inhalant interaction, and particulatedistribution.

We used multi-material 3D printing to produce a nasopharynx castcomplete with vestibular, inferior turbinate, medial turbinate, superiorturbinate, and nasopharynx regions internally, and nose and facialfeature externally. A collection of software was used to convertcomputed tomography (CT) scan-based stereolithography (STL) file tocreate a face/nasopharynx base object, as well as the associatedinternal and external components.

FIG. 3A is a 3D view of the construction of the nasopharynx base object300. FIG. 3B is a top front view of the nasopharynx base object 300 ofFIG. 3A. FIG. 3C is a left view of the nasopharynx base object 300 ofFIG. 3A. FIG. 4A is a front view of a portion of 3D printed nasal cavity400 contained in slide 301 a. FIG. 4B is a front view of a portion of 3Dprinted nasal cavity 400 contained in slide 301 b, which isrepresentative of other non-end slides 301 c-301 g (FIGS. 3A-3C). FIG.4C is a front view of a portion of a 3D printed pharynx 402 of the 3Dprinted nasal cavity 400 contained in slide 301 h.

With primary reference to FIGS. 3A-3C, the nasopharynx base object 300was sectioned into eight (8) slides. The nasopharynx base object 300 wassectioned into eight (8) slides 301 a-301 g, one (1) section 301 acontaining the external facial features, 6-mm sections spanning the 3Dprinted nasal cavity 400 (FIGS. 4A-4C), and one 12-mm slide 301 hintegrating a 3D printed pharynx 402 (FIG. 4C). The slides 301 a-301 gwere aligned on an aluminum railing 310 to allow easy manipulation ofslides 301 a-301 h. Four partially threaded screws 312 a-312 d piercingeach slice 301 a-301 h allow for compression when tightened. Withreference to FIGS. 4A-4C, respective rubber-like gasket 404 was fusedonto the front of each slice 301 b-301 h to allow airtight seal ofentire nasopharynx base object 300 (FIGS. 3A-3C).

FIGS. 5A-5B respectively depict a right side view and a left side viewof the nasopharynx base object 300. Probing regions or channels wereinserted into the thickness of the slides 301 a-301 f. Specific sitesfor sampling at the superior, middle, and inferior meatus, the mainpassages or openings within the nasal cavity 400 were identified throughexamination of the CAD model. These locations were selected to provideseamless integration with probes and result in minimal interference withthe internal nasal structures and passages. With reference to FIG. 5A, achamber 501 of nasopharynx base object 300 is depicted transparently toexpose superior turbinate 503 of 3D printed nasal cavity 400 accessiblefrom the right via probe access bores 504 a-504 c respectively in slides301 b, 301 c and 301 e. Medial turbinate 505 of 3D printed nasal cavity400 is accessible from the right via probe access bores 504 d-504 irespectively in slides 301 a-301 f. Inferior turbinate 507 of 3D printednasal cavity 400 is accessible from the right via probe access bores 504k-504 m respectively in slides 301 b-301 e. With reference to FIG. 5B,the superior turbinate 503 is accessible from the left via probe accessbores 504 n-504 o respectively in slides 301 c and 301 e. Medialturbinate 505 is accessible from the left via probe access bores 504p-504 u respectively in slides 301 a-301 f. Inferior turbinate 507 of 3Dprinted nasal cavity 400 is accessible from the left via probe accessbores 504 v-504 y respectively in slides 301 b-301 e.

FIG. 6A depicts a front view of slide 301 a having one right probeaccess bore 304 d and one left probe access bore 304 p. FIG. 6B depictsa front view of slide 301 b having three right probe access bores 304 a,304 e, and 304 j and three left probe access bores 304 n, 304 q, and 304v. FIG. 6C depicts a front view of slide 301 c having three right probeaccess bores 304 b, 304 f, and 304 k and two left probe access bores 304r and 304 w. FIG. 6D depicts a front view of slide 301 d having tworight probe access bores 304 g and 304 l and two left probe access bores304 s and 304 x. FIG. 6E depicts a front view of slide 301 e havingthree right probe access bores 304 c, 304 h, and 304 m and three leftprobe access bores 304 o, 304 t, and 304 y. FIG. 6F depicts a front viewof slide 301 f having one right probe access bore 304 i and one leftprobe access bore 304 u.

FIG. 7A depicts a side view of a cylindrical rod 701 a of a particularlength corresponding to a probe access bore and having a perpendiculardistal face 703 a that aligns with a perpendicular contour at a locationof a 3D printed nasal cavity 705. FIG. 7B depicts a side view of acylindrical rod 701 b of a shorter particular length corresponding to ashorter probe access bore and having a non-perpendicular distal face 703b that aligns with a non-perpendicular contour at a location of the 3Dprinted nasal cavity 705. Cylindrical rod 701 a (FIG. 7a ), 701 b areresting inserts that seal process access bores that are not accessed.

FIG. 7C depicts an anemometer 710 being inserted through an anemometerinsert 711 a that was custom design to fit a commercial miniaturespherical probe of a flow meter (omni-directional velocity probe, mini Ishape, V, Kanomax, 6551-2G), permitting sampling of air flow velocity.The anemometer insert 711 a has a perpendicular distal face 713 a. FIG.7D depicts the anemometer 710 inserted through the anemometer insert 711a. FIG. 7E depicts the anemometer 710 inserted through an anemometerinsert 711 b that has a non-perpendicular distal face 713 a.

FIG. 7F depicts a tissue insert 720 having a cylindrical shaft 721 of alength selected to position a tissue holder 722. The tissue holder 722has distal disc recession 724 sized to receive a gel medium 726 and aliving tissue sample 728. In One or embodiments, the disc recession 724has a diameter of 4.5 mm and a thickness of 1.5 mm that can hold a gelmedium 726 covered with a living tissue sample 724 of circular nasaltissue explants or cutouts of stacked nasal epithelial cell layers. Tominimally interfere with the intricate internal nasal cavityarchitecture, all inserts were designed with custom contoured of endsthat matched internal anatomical geometry of the nasal cavity.

FIG. 8A is an exploded 3D view of the bi-directional fan 111 thatincludes a stand 800 that includes a motor encasing 802 that mounts toback cover 804 that in turn attaches to a front cover 806 having a mount808. The back and front covers 804, 806 encompass a fan blade 810. FIG.8B is a side view of the bi-directional fan 111 depicting assembled backand front covers 804, 806 to form a top air port 812 and a bottom airport 814. The top and bottom air ports 812, 814 operate either as an airinlet or air outlet depending on the direction of spin of the fan blade810. FIG. 8C is a back view of the bi-directional fan 111 depicting amotor 816 that includes motor set-screw and ball bearing to stabilizefan blade spin. FIG. 8D is a front view of the bi-directional fan 111depicting the mount 808 that is attachable to a side wall of the fancontainer 112 (FIG. 1).

The bi-directional fan 111 (FIGS. 8A-8D) simulates inhalation andexhalation rates. In one or more embodiments, the motor voltage andcurrent flow direction are regulated via Arduino Uno microcontroller,while breathing pattern waveform, rate, duration, etc. are all executedvia a graphical user interface (GUI). FIG. 9A depicts a normal breathinginhalation/exhalation airflow patterns 900. In particular, an upper plot902 presents volume of air moved as a function of time and a lower plot904 presents a rate of change in volume as a function of time. FIG. 9Bdepicts a forced breathing inhalation/exhalation airflow patterns 920.In particular, an upper plot 922 presents volume of air moved as afunction of time and a lower plot 924 presents a rate of change involume as a function of time.

FIG. 10 is a screen shot 1000 of a Matlab graphical user interface (GUI)used to control flow modes and sequence. The application sharesinformation directly to the simulator device via a USB serialconnection. Upon opening the application, connection to the Arduino isestablished by specifying the appropriate communication port (COM port).From this point, the fan is fully controllable with a wide selection ofcyclic and non-cyclic functions. The user is able to select the waveformshape and the inhale and exhale flow rate amplitude, which directlycorrelates to the voltage received by the fan.

Unlike typical nasal cast models, this innovative biohybrid upperrespiratory model allows for more accurate representation ofphysiological breathing functions coupled with spatiotemporally relevanttissue analysis. However, like general nasal cast models, there areseveral future modifications that can be added to the design to supply abreathing systems closer to the bonifide nose. First, the nasal cavityregion is fixed and rigid (Doody et al 2008). Therefore, preset forms ofnasal casts are unable to mimic the natural cyclic alternation in openand closed caliber and high and low airflow of the nostrils (Eccles2000, Beule 20110). It is possible to replicate the nasal cycling usingflexible materials and including mechanical structures to facilitateexpansion and contraction of a nostril opening. Second the printablematerials do not exhibit the stiffness of hard and soft regions of thehuman nose. Sander et al. created a nasal cast, for patient education,with rigid and flexible materials to represent the hard and soft tissuesexisting within the nasal cavity (Sander et al 2017). We have used thesame materials for the existing design, but the rigid materials was usedfor the bulk nasal cavity design and the flexible materials tofacilitate an airtight seal between individual slides. With an everincreasing production of diverse printable materials, possessing a rangeof mechanical properties, it is possible to create a nasal simulatorcontaining regions that match the hard and soft tissue moduli of abonifide nasal cavity.

The nasal cavity geometry should be carefully determined, based onresearch needs. Some researchers have determined geometries of a“standard” nasal cavity by averaging the geometries from 3D cavitymodels derived from 30 patients (Liu et al 2009). Also, with 3Dprinting, it is possible to create group or patient-specific replicas toaccount for possible variations in research results due to factors suchas age, race, sex or existing nasal anomalies (e.g. presence of nasalpolyps).

CONCLUSIONS: A 3D printed model of nose simulator chamber was designedand created using rapid prototyping, machining and programming methods.The technique utilized 3D mesh and modeling software along with rapidinnovation 3D printers to generate single material structures Theprotocol reported here focuses on converting Nasal Cavity CT data intothe 3D printed design for testing. 3D printing of nose simulator chamberis a prodigious design for testing of patterned distribution and flowpatterns of inhaled airstreams within the nasal cavity, and theinteraction of inhalants with nasal mucosa cells or tissue.

Ongoing work will include validation of this nose simulator system bycharacterizing the achievable flow rates within the nose simulatordevice (using the commercial anemometer tip). Additionally, we willintegrate nasal tissue or tissue-like (multi-cell layers) into the“tissue” probes and characterize the variation of cellular viabilitywith time.

Prospective experiments include the evaluation of different potentiallyhazardous environmental conditions, including hypoxia, airbornenanoparticles, and exposure to volatile organic compounds. Here we havemarried electronic and biological elements in a proposal to develop arobotic biohybrid upper respiratory model. In doing so, we strive toraise the achievement bar for bioengineering technologies a bit higherby pushing the development of more life-like robotic devices that doublysupply advanced mechanical function and biological architecture that arenative to humans.

Additional information is provided in the following references, thedisclosure of which is hereby incorporated by reference in theirentirety:

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While the disclosure has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the disclosure. Inaddition, many modifications may be made to adapt a particular system,device or component thereof to the teachings of the disclosure withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the disclosure not be limited to the particular embodimentsdisclosed for carrying out this disclosure, but that the disclosure willinclude all embodiments falling within the scope of the appended claims.Moreover, the use of the terms first, second, etc. do not denote anyorder or importance, but rather the terms first, second, etc. are usedto distinguish one element from another.

In the preceding detailed description of exemplary embodiments of thedisclosure, specific exemplary embodiments in which the disclosure maybe practiced are described in sufficient detail to enable those skilledin the art to practice the disclosed embodiments. For example, specificdetails such as specific method orders, structures, elements, andconnections have been presented herein. However, it is to be understoodthat the specific details presented need not be utilized to practiceembodiments of the present disclosure. It is also to be understood thatother embodiments may be utilized and that logical, architectural,programmatic, mechanical, electrical and other changes may be madewithout departing from general scope of the disclosure. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present disclosure is defined by the appendedclaims and equivalents thereof.

References within the specification to “one embodiment,” “anembodiment,” “embodiments”, or “one or more embodiments” are intended toindicate that a particular feature, structure, or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present disclosure. The appearance of such phrases invarious places within the specification are not necessarily allreferring to the same embodiment, nor are separate or alternativeembodiments mutually exclusive of other embodiments. Further, variousfeatures are described which may be exhibited by some embodiments andnot by others. Similarly, various requirements are described which maybe requirements for some embodiments but not other embodiments.

It is understood that the use of specific component, device and/orparameter names and/or corresponding acronyms thereof, such as those ofthe executing utility, logic, and/or firmware described herein, are forexample only and not meant to imply any limitations on the describedembodiments. The embodiments may thus be described with differentnomenclature and/or terminology utilized to describe the components,devices, parameters, methods and/or functions herein, withoutlimitation. References to any specific protocol or proprietary name indescribing one or more elements, features or concepts of the embodimentsare provided solely as examples of one implementation, and suchreferences do not limit the extension of the claimed embodiments toembodiments in which different element, feature, protocol, or conceptnames are utilized. Thus, each term utilized herein is to be given itsbroadest interpretation given the context in which that terms isutilized.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The description of the present disclosure has been presented forpurposes of illustration and description, but is not intended to beexhaustive or limited to the disclosure in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope of the disclosure. Thedescribed embodiments were chosen and described in order to best explainthe principles of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. A nasal simulator comprising: a three-dimensional(3D) printed nasal cavity within based on diagnostic imagery of a humannasal cavity; a fan system positioned to mimic air flow through thehuman nasal cavity; a first probe access bore formed through the 3Dprinted nasal cavity to a first location having a first internalcontour; and an anemometer insert having an outer diameter sized to beslidingly received in and to pneumatically seal the first probe accessbore, the anemometer insert having a distal contour that aligns with thefirst internal contour of the 3D printed nasal cavity, the anemometerinsert having a longitudinal bore that is sized to receive a probe of ananemometer to detect characteristics of the air flow through the 3Dcavity.
 2. The nasal simulator of claim 1, wherein the first probeaccess bore and the anemometer insert comprise a teeth and groove lock.3. The nasal simulator of claim 1, further comprising: a second probeaccess bore formed through the 3D printed nasal cavity to a secondlocation; and a resting insert having an outer diameter sized to beslidingly received in and to pneumatically seal the second probe accessbore, and the resting insert having a distal contour that aligns withthe second internal contour of the 3D printed nasal cavity.
 4. The nasalsimulator of claim 1, further comprising: a second probe access boreformed through the 3D printed nasal cavity to a second location; and atissue insert having an outer diameter sized to be slidingly received inand to pneumatically seal the second probe access bore, and the tissueinsert having a distal end cavity that receives a tissue insert to forma distal contour that aligns with the second internal contour of the 3Dprinted nasal cavity.
 5. The nasal simulator of claim 1, wherein thetissue insert comprises a gel medium and a nasal tissue sample.